The field of the present invention is related to the measurement of biological samples.
Prior methods and apparatus of measuring metabolites are less than ideal. Although the prior methods and apparatus can be used to determine amounts of metabolites in patients, in many instances the required sample size is larger than ideal. For example, metabolic panels, toxicology screens and other tests can require removal of more blood from the patient than would be ideal. Also, the cost and complexity of the measurement apparatus can be greater than would be ideal such that fewer patients are measured than would be ideal in at least some instances. Although in home monitoring can be used, the invasiveness and discomfort of pricks with sharp objects and other inconveniences can result in less than ideal user satisfaction. Also, the fluid measured at locations away from the finger tips may comprise interstitial fluid that can have amounts of metabolites that differ from blood amounts in at least some instances.
Although Raman spectroscopy has been proposed to measure biological samples, the prior methods and apparatus provide less than ideal measurements in at least some instances. For example, Raman spectroscopy relies on light scatter and the signal to noise ratio and sample measurement duration can be less than ideal with the prior Raman spectroscopy methods and apparatus. Also, biological samples can degrade, and the prior methods and apparatus can provide less than ideal amounts of sample degradation and may not adequately address degradation of biological samples in at least some instances.
In light of the above, it would be beneficial to provide improved methods and apparatus of measuring biological samples. Ideally such methods and apparatus would provide lower detection limits of metabolites in samples, decreased invasiveness and discomfort, decreased complexity, increased accuracy and decreased cost.